Principle Of Conservation Of Energy Research Articles

Formulations of the elastodynamic equations in anisotropic and multiphasic porous media from the principle of energy conservation

Abstract Elastodynamic equations have been formulated with Newton's second law of motion, Lagrange's equation, or Hamilton's principle for over 150 years. In this work, contrary to classical continuum mechanics, a novel strategic methodology is proposed for formulating general mechanical equations using the principle of energy conservation. First, based on Hamilton's principle, Hamilton's equations, Lagrange's equation, and the elastodynamic equation of motion are derived in arbitrarily anisotropic and multiphasic porous elastic media, for the first time. Secondly, these equations are all formulated using the principle of energy conservation for the related media. Both formulation results using the two kinds of principles are compared and validated by each other. The advantages of our methodology lie in that the elastodynamic equation of motion, Lagrange's equation, and Hamilton's equations in continuum mechanics are directly formulated using a simple constraint of energy conservation without introducing variational concepts. It is easy to understand and has clear physical meanings. Our methodology unlocks the physics essences of Hamilton's principle in continuum mechanics, which is a consequence of the principle of energy conservation. Although the linear stress–strain constitutive relation is considered, our methodology can still be used in a nonlinear dynamical system. The methodology also paves an alternative way of treating other complex continuous dynamical systems in a broad sense. In addition, as an application, the continuity conditions at various medium interfaces are also revisited and extended using our proposed approach, which explains the law of reflections and refractions.

Numerical study on the mixing process of hot desulfurization slag and converter steel slag

Slag mixing technique is a process that eliminates the lumping phenomenon of slag and iron in desulfurization slag. This process is conducted by mixing the high-temperature converter slag and iron desulfurization slag. The slag crushing difficulty is remarkably reduced after mixing. This technique eliminates the lumping phenomenon in the iron desulfurization slag. A numerical model based on Eulerian multiphase flow was established for the mixing process. The model obtained the characteristics of the phase field distribution inside the slag tank. The slag expansion phenomenon was identical with experimental results. A simplified temperature dropping model of slag mixing process was established based on the principle of energy conservation. According to this simplified model, the time dependence of the chemical reaction rate and temperature was investigated. The simplified model built by multifactor regression method can effectively predict the chemical reaction rate and temperature change under the following conditions: converter slag with an initial mass of 4–12 t, an initial iron oxide content of 20%–40%, an iron desulfurization slag mixing volume of 1–5 t, and an iron desulfurization slag mass flow rate of 0.1–1 t/s. The simplified model provides basic physical parameters for post-processing while ensuring safe production.

Energy Conservation Principle from the Perspective of the Energy Structure Theory

In this paper, the energy conservation principle is investigated from the perspective of the energy structure theory. Energy structure theory presents the basic equation as energy structure equation has been developed to study physical processes considering effects of the second law of thermodynamics directly. Energy components are used as basis of the energy structure equation. In this paper, to investigate the energy conservation principle using the energy structure equation, the variation of the energy structure equation is studied in different paths for the same amount energy applying to the system. In fact, a quasi-static path is used as a reference path, and other paths are studied using this reference when the same amount of energy is applied to the system in different conditions. Using this approach, in fact, energy conservation principle is applied to the energy structure equation, and therefore, the resultant relation has the first and second laws of thermodynamics as its basis together that has been developed in one relation. Therefore, the extracted relation will be a bidirectional relation that means all processes must satisfy this relation and vice versa.

Multi-Irradiance: A Method for Simultaneous Measurement of the Temperature and Spectral Emissivity of High-Temperature Targets in SWIR.

The currently used energy methods in spectral emissivity measurement are susceptible to the difference in temperature between the target and the reference blackbody. It is also limited by the state of the observation target and observation. This paper introduces the irradiance condition, while using the correlation between the information of emission energy and reflected energy of the high-temperature target. Based on the principle of radiative transmission and energy conservation, the relationship between the emissivity and bidirectional reflectance factor (BRF) was used to perform the retrieval of emissivity and temperature. An experimental device was designed, and graphite and rock were considered to verify the feasibility of the experimental scheme. The error of emissivity and temperature of both targets were, respectively, less than 5% and 0.5%, due to the Lambertian assumption, and the systematic errors had negligible impact on the retrieval. This verifies that the experimental observation method and scheme is reasonable.

Cognitive bias in physics, with respect to Einstein’s relativity, is demonstrated by the famous experiment of Pound and Rebka (1960), which in reality refutes Einstein’s general relativity

Einstein’s general relativity postulates that, at each positon within a gravitational field, we must measure the same frequency f 0, but seen from a distance, the frequency at the position of another gravitational potential is different from f 0. As gravity decreases with the increase in the distance from Earth, in the Pound‐Rebka experiment at the top of the tower, the frequency of electromagnetic radiation must be higher than at the bottom. If electromagnetic radiation was able to have the same frequency f 0 at the top of the tower as at the bottom of the tower, an observer at the top of the tower would have to be able to increase gravity to the same level that gravity has at the bottom. But the decrease in gravity with an increase in the altitude cannot be reversed. It is demonstrated that the relativistic interpretation of the Pound‐Rekba experiment showing a doubling of the gravitational frequency shift for “two-way” observations violates the principle of energy conservation, whereas the classical interpretation of the experiment identifies the doubling of the gravitational frequency shift as a pure mathematical effect that has no physical reality, which always occurs when we subtract relative differences with opposite algebraic signs from each other. It is shown that Einstein’s general relativity only seemingly corresponds with reality; thus, gravitational frequency (time) shifts must be interpreted according to classical considerations.

Determination and interpretation of parameters of double-bud sugarcane model based on discrete element

Physical parameters of cane seeds are an important basis for the design calculation and simulation analysis of the seed meter. The accuracy of discrete element simulation depends on the discrete element parameters. In this study, based on the principle of energy conservation, discrete element parameters of cane-cane and cane-steel are experimentally studied by means of the inclined plane method and high-speed camera technology. The ranges of the static friction coefficient, rolling friction coefficient and restitution coefficient are obtained. In order to determine the discrete element simulation parameters, the Plackett-Burman test is used to evaluate six factors. Three significant factors of the cane-cane static friction coefficient, cane-cane rolling friction coefficient, and cane-steel restitution coefficient are selected. Then, the steepest climb test is used to approximate the optimal response region. Finally, the Box-Behnken response surface method is used to determine the values of three significant factors. It can be seen from the verification experiments that the optimized cane-cane static friction coefficient, cane-cane rolling friction coefficient, and cane-steel restitution coefficient are 0.19, 0.035, and 0.351, respectively. The repose angle under this parameters is 34.051° and the relative error is 2.7%. Therefore, the data accuracy is high. The experimental results can provide a theoretical basis for the design calculation and simulation analysis of the seed meter.

«Мнимые противоречия»: предисловие С. А. Рачинского к книге Чарльза Дарвина «Происхождение видов»

This publication introduces the preface by Sergey Rachinsky, a profeccor of the Moscow University, to the book of Charles Darwin «On the Origin of Species». Rachinsky is best known in Russia as an educator and the founder of the school in Tatevo, Tver Oblast, and also as a founder of the temperance society in Tatevo. But in his correspondence Rachinsky repeatedly touches on religious and philosophical matters. For example, he gets into an argument with people like Vasily Rozanov and Leo Tolstoy. In addition, Rachinsky left some religious and philosophical works that are still in manuscript. This unpublished work was written in the 1882. Rachinsky touched upon the issues related to Darwin's theory of natural selection. Some of them had been raised before by his famous Russuan contemporaries, such as Nikolay Strakhov, Dmitry Pisarev, Kliment Timiryazev, Fyodor Dostoevsky, Konstantin Pobedonostsev. By the time that the preface was written, disputes over Darwin had been going on more than two decades. Disputes were related not only to «On the Origin of Species», but also to Darwin's later works. At the beginning of the preface Rachinsky commends the theory of natural selection which had proposed a general law of classification of living beings. The main body of the preface is devoted to Darwin's attempt to incorporate human into a genealogical tree of animal species. Rachinsky points out that Charles Darwin tried to gather some animal's characteristics and to work out the image not merely of a human being but of a Christian. Rachinsky calls it “a futile exercise”. He indicates that the inner human world has no precedent in the animal kingdom and believes that it is a miracle. Citing the principle of energy conservation as an example, and aims to show that “a miracle” exists in this theory. At the end of the preface author points out that Darwin's theory is applicable in some areas of science and it has no any contradictions with Christianity. He also points out to critics of this thesis that Church poses no restrictions to the exploration of nature.

A methodology to predict the run-out distance of submarine landslides

In this paper, the method of computational fluid dynamics (CFD) is proposed to simulate a fluidized submarine landslide with shear thinning non-Newtonian fluids over a seabed under different contact conditions in the ambient water. The CFD method is first validated using data of physical channel and non-Boussinesq lock-exchange experiments with different rheological characteristics and is found to provide good accuracy. Various CFD-based experiments with different initial velocities of the submarine landslide and different seabed contact conditions are then performed systematically. During the movement of the submarine landslide in ambient water, stress state and causes of the submarine landslide mass are revealed, and the submarine landslide-seabed contact relation is clarified as a decisive influencing factor. Furthermore, based on the principle of energy conservation, a methodology to predict the run-out distance of the submarine landslide mass by using the initial geometry of the submarine landslide masses with different scales and the total initial kinetic energy (including the initial kinetic energy and the gravitational potential energy difference caused by the self-slumping) of the submarine landslide mass is presented, equations to quantify the process are established, and the proposed methodology and equations are validated by the numerical result, which provides a significant basis for the prediction of marine engineering geological and hydrodynamic hazards with special reference to submarine landslides.

A quantitative study on the thermomechanical coupling effect of elasticity and plasticity of polymethyl methacrylate

Quantitative study on the elastic and plastic thermomechanical coupling effect of solid materials has important theoretical significance for monitoring the deformation state and stability evaluation of engineering components. In this study, the sample is made of polymethyl methacrylate (PMMA), and uniaxial compression experiments are carried out. The sample experiences the elastic state and then the plastic state until the failure of the sample. The thermoelastic effect and thermoplastic effect in the deformation process of PMMA materials are monitored by infrared thermography and digital speckle system (DIC). That is, the relationship between the reversible elastic temperature change ΔTe and average stress change Δσm, and the relationship between the irreversible plastic temperature rise ΔTp and the dissipated energy ΔUp during the failure deformation process. The results show that when the sample is in the elastic regime, there is only elastic temperature change ΔTe inside the sample. When the sample enters the plastic deformation regime, the total temperature change ΔT includes elastic temperature change ΔTe and plastic temperature change ΔTp, and the temperature change has an obvious memory effect on the previous maximum load. When the previous maximum load exceeded, ΔTp increases rapidly. When the load P is removed, ΔTe disappears, and ΔTp remains. Combined with the theory of thermodynamics and solid mechanics, starting from the 3D stress state, the approximate linear incremental relationship between Te and σm, and the accurate exponential total quantity relationship are derived. The incremental relationship and the full relationship combined with thermodynamic theory and the energy conservation principle, the relationship between the overall plastic temperature rise ΔTp and local plastic temperature rise ΔTpmax of the sample and the energy dissipation value ΔUp experienced by the sample and the local dissipation specific energy Δup is obtained. The theoretical calculation results of ΔTe and ΔTp are in good agreement with the experimental results. The research results can provide a new method for monitoring and identifying the stress and deformation state of engineering components through the temperature field.

Warp and blur imaging model consistent with the three constraints of imaging through refractive turbulence.

Point spread function (PSF) for imaging through inhomogeneous refractive medium, such as atmospheric turbulence, is bounded by three constraints [Opt. Eng.52, 046001 (2013)OPEGAR0091-328610.1117/1.OE.52.4.046001]. PSF is non-negative, band-limited, and the third constraint, related to the energy conservation principle, warrants the absence of fluctuations in the image of a uniformly bright object. We develop a version of the common warp and blur model for the anisoplanatic image distortions by turbulence that satisfies these three constraints. In order to comply with the third constraint, our model supplements warp and blur by a random PSF power, which was found to be related to the Jacobian of the warp field. We illustrate statistics of the warp and blur using a simple example of anisoplanatic phase screen.

An accurate and numerically efficient time-varying mesh stiffness model for modified straight bevel gear under load

Gear time-varying mesh stiffness (TVMS) plays an important role in the analysis accuracy of a gear transmission mechanism. In previous research, the TVMS of a modified straight bevel gear (SBG) was mainly obtained by the finite element method (FEM), whose computation time is usually long to ensure computational accuracy. By contrast, this work proposes a fast calculation method with high accuracy for the TVMS of a modified SBG. First, B-spline surfaces are introduced to reconstruct a modified SBG using discrete tooth surface points. Next, based on the tooth contact analysis and loaded tooth contact analysis, combined with energy conservation principle and infinitesimal method, a semi-analytical instantaneous single mesh stiffness (SMS) model for the modified SBG is derived. Then, using the additional deformation compatibility condition and principle of force balance, the calculation method of the TVMS of the modified SBG is obtained. Finally, a comparison of the mesh stiffness calculation results between the method of this study and that of FEM is completed. The results show that the semi-analytical TVMS model used in this study can be accurately and quickly solved.

SOME PHYSICAL LAWS SUCH AS CONSTANT SPEED OF LIGHT CAN BE EXPLAINED ACCORDING TO THE PRINCIPLE THAT ANY MATTER MUST HAVE FINITE ENERGY

In this paper, a physical principle that any matter must have finite energy is first proposed, which is expressed that any matter must have energy and the energy is finite under any conditions. According to this principle and energy conservation principle, some physical laws with unclear reasons are explained: The mass of a composite particle is greater than the sum of the mass of component particles; The potential energy of a composite particle is smaller than the potential energy sum of the component particles; Any massless matter must move at the speed of light under independent conditions; The velocity of static field without mass can be zero; Deriving inverse square law of massless field strength; Conditions for electromagnetic oscillation to form electromagnetic waves.

An Approach For Unity Field Theory With New Quantumvacuum Energy Aether Concept

Theories of relativity and quantum physics are basing on some complex abstract mathematical formalism which can be quite confusing and not always satisfactory concerning the interpretation of observed corresponding physical effects. For a revised approach of them, we present a new quantum vacuum energy Aether concept we will discuss qualitatively avoiding some abstract mathematical formalism often far from intuitive physical common sense. This is essentially concerning: the relative velocity of light and the Aether disprove, the particle/wave duality, the single particle interference quantum phenomena, the generalized confusion between absolute quantum determinism and undetermined probabilistic measurements of quantum states and the paradoxical possibility for a same quantum system to have at same time different states. Notwithstanding different suggested flaws about the principle of energy and impulse conservation and concerning the optical doppler effect and the postulate of an absolute light speed limit which is contradicted with some observation of superluminal particle transportation velocity. Paradoxical aspects of both theories of the quantum mechanics and theory of relativity are suggested to be sorted out with the rehabilitation of an absolute space reference and a newly defined Aether concept, basing on the equivalence between density of mass and density of quantum vacuum energy. Different aspects of the Field Theory and wave /mass /electric particles interactions are suggested to be interpreted in terms of Aether hydrodynamical energy displacement, fluctuation and waves. Electric charge and mass of particles and their kinetic energy are described in terms of energy of an associated Aether 3D transversal and/or longitudinal wave-packet moving with its group velocity in form of Aether vortices. This model is expected to sort out contradiction about different quantum phenomena and to open the way for new description and interpretation of corresponding new experimental results.

DESIGN OF BUBBLE IRRIGATION SYSTEM WITH EMITTERS AT GROUND LEVEL

In the Brazilian semi-arid, sustainable growth rates and higher standards of living in society may be attained by the use of irrigation aiming at obtaining the best economical function without disregarding several factors, such as labor, soil, and water supply. The objective of this work is presenting an alternative design procedure for low-head bubble irrigation systems so as to make the technology more accessible to users. An electronic spreadsheet was developed and made available for sizing laterals and delivery hoses at ground level based on the principles of mass conservation, energy conservation and friction head loss. 9 combinations of spacings between plants and between rows were used with different lateral lengths, resulting in 22 designs operating at 9.8 kPa (1 m.w.c). Designs were subjected to hydraulic and efficiency tests. Uniformities of water application were computed using Christiansen’s uniformity coefficient and distribution uniformity coefficients. Designs were ranked according to the proposed classification of Mantovani. Irrigation uniformities, above the recommended limits and with low variability across designs, allow us to conclude that the design procedure for the proposed irrigation system is feasible.

Numerical modeling and parametric study of a dual purpose underground thermal battery

Integrating thermal energy storage with building energy systems can enable flexible building electric demands at buildings to help mitigate the mismatch between electricity supply and demand. A novel building heating and cooling system that integrates a dual-source heat pump with hybrid thermal storage named dual-purpose underground thermal battery (DPUTB) has been developed for reshaping building electric demands. The proposed DPUTB integrated geothermal heat pump system is an original innovation that enables Grid-interactive Energy Efficient buildings. This paper focuses on the study of the novel DPUTB. The DPUTB works as both a thermal storage tank (an inner tank) and a ground heat exchanger (an outer tank separated from the inner tank by the insulation material). High fidelity and computationally effective models are needed to predict the performance of the novel DPUTB. This study has developed a simplified dynamic model for the DPUTB according to heat transfer and energy conservation principles and validated it by using experimental data obtained from testing a small-scale DPUTB apparatus. A parametric study was conducted to identify a design that can achieve the target thermal storage performance of load shift and energy efficiency. The parametric study results show that the inner tank shell thermal conductivity and the phase change material's melting point are the two most influencing factors on the performance of the DPUTB. One single full-size DPUTB with the identified design could provide 1-ton cooling (3.51 kW) with the supply temperature lower than 11 °C for 4 hours in summer after being fully charged in 8 hours. The inner tank filled with phase change material is for cooling thermal storage as a latent tank in the design. However, its capacity can be as high as 60 MJ as a sensible water tank for heating storage in winter. In the future study, the DPUTB model will be incorporated into the dual-source heat pump system for evaluating the overall system performance of demand side management in the long term.

Principles of Classical Mechanics Describe Gyroscopic Effects

The unexplainable motions of the simple spinning top toy, boomerang, and other spinning objects attracted people since the time of ancient civilizations. The intricated motions of the rotating objects and the action of the unknown forces were named gyroscopic effects. The physicists and mathematicians tried to solve them beginning from the Industrial Revolution until our time. One gyroscopic effect which is the side motion of the spinning disc was described by L. Euler and presented in the world encyclopaedias as the fundamental principle of gyroscope theory. The origin of gyroscopic effects is more sophisticated than in published and simplified theories. Analytical solutions to other gyroscopic effects were described only in our times. The system of the interrelated inertial torques generated by the rotating mass acts on the spinning object based on the principle of mechanical energy conservation. This system presents the fundamental principles of gyroscope theory.

Numerical simulation of formation water salinity redistribution in fractured shale reservoirs during hydraulic fracturing

Using numerical simulation methods to predict the distribution of salinity in reservoirs during hydraulic fracturing is challenging due to the dynamic propagation of hydraulic fractures (HFs), random distribution of natural fractures (NFs), multiphase heat and mass transfer behavior, and various connotative mechanisms. In this study, to accurately predict changes in matrix salinity during hydraulic fracturing, a multiphase heat and mass transfer model of HFs, the matrix, and NFs was derived based on the principles of material and energy conservation, the electro-chemical potential, and the embedded discrete fracture model (EDFM). The model considers the dynamic propagation of HFs, multiphase flow, chemical osmotic pressure, capillary pressure imbibition, heat conduction, and NFs. The prediction model of solute salinity developed in this study is then verified using previous findings. Finally, the effects on the salinity distribution within the matrix by volume differences of injected fracturing fluid, salinities of the fracturing fluid, number of NFs, temperatures of fracturing fluid, and mechanisms were analyzed. The results show that the injection volume and temperature of the fracturing fluid, and the number of NFs are positively correlated with the decreasing range of salinity in the matrix and damage range of clay swelling, while the salinity of the fracturing fluid is negatively correlated with the decreasing range of salinity in the matrix and the damage range of clay swelling. During fracturing, the random distribution of NFs and local strong heterogeneity hinder prediction and cause strong heterogeneity in the distribution of salinity, pore pressure, and matrix temperature. At the same time, the pressure gradient, chemical osmotic pressure, and imbibition of capillary pressures under mixed wetting decrease salinity within the matrix and aggravate clay swelling damage. Of the three mechanisms affecting the salinity distribution within the matrix, the pressure gradient has the greatest contribution, followed by osmotic pressure and capillary pressure imbibition. The results of this study provide insights into the theoretical prediction of salinity distribution in the matrix after fracturing and hence the design of HFs.

New Framework of RoCoF-FD for Wideband Stability Evaluation in Renewable Energy Generators With Virtual Impedance Control

This research proposes a new perspective for identification of wideband stability in virtual synchronous generator (VSG) with virtual impedance control strategy. At first, the drawback of magnitude-phase-motion-equation (MPME) of grid-forming VSG system is briefly discussed. Then, based on the derived MPME model, a RoCoF-FD framework, which includes two most important indices of frequency performance, e.g., rate of change of frequency (RoCoF) and frequency nadir/deviation (FN/FD), is established to illustrate the interaction between RoCoF and FD based on feedback effect. Moreover, the vector analysis can quantitatively sketch the dynamics of RoCoF impacted by the FD via the loop of feedback effect. In addition, the secure operation regions are defined for the VSG system. It is found that system has a higher risk of oscillation instability when ratio of grid resistance divided by grid inductance gets smaller. However, greater ratio will lessen grid strength/stiffness, which will trigger aperiodic loss of synchronization. To cope with such issues, an adjustable-parameter virtual impedance control strategy (APVICS), based on principle of energy conservation, is proposed to dampen oscillation as well as avoid loss of synchronization of the system, thereby enhance damping behaviors and grid stiffness. Finally, theoretical analysis is validated experimentally.

Quantum-Mechanical Description of Physical Reality Shall Be Considered Complete

After the deduction and comparison of wave motions of classical particles and quantum particles, we prove that there are two restrictions applied to both classical particles and quantum particles. Both restrictions are just to ensure energy conservation principle of the wave motion. The Heisenberg’s famous inequality was nothing to do with the measurements of particle’s position or mentum, the restriction of the inequality is just the lower limit of the wave motion. His uncertainty principle was not correct from both mathematical and physical perspective. Based on the mathematic analysis and logic reasoning process review, we conclude that all the Heisenberg’s uncertainty principle, Born rule and Bohr’s complimentary principle were not correct. Even for a quantum particle, at any time, it must be classically localized instead of non-local. Without the Copenhagen interpretations, the quantum mechanics shall still be considered complete according to EPR’s criteria which are used to verify the completeness of a physics theory. The particle-wave duality of quantum particles comes from their inner features of electric vector(s).

Calculation for Permanent Displacement of Single Slip Surface of Multi-Stage Loess Slope Based on Energy Method

At present, there are still some gaps in the theoretical calculation of the permanent displacement of the multi-stage loess slope under the action of earthquake. Therefore, this paper firstly uses the GEO-Studio finite element software to explore the influence of the comprehensive slope rate on the permanent displacement when the slope rate of each grade of multi-stage loess slope changes and the stage of multi-stage slope changes. The results show that it is feasible to use the comprehensive slope rate to calculate the permanent displacement of the sliding body of the multi-stage loess slope under the action of earthquake. On the basis of this conclusion, in order to simplify the calculation of permanent displacement of potential sliding soil, the other geometric parameters of the multi-stage loess slope are replaced by the comprehensive slope rate, combined with the Newmark slider displacement analysis method and energy conservation principle, and then the calculation method of permanent displacement of potential sliding soil of multi-stage loess slope under the action of earthquake is deduced. Through an example, the permanent displacement calculated by the proposed algorithm are compared with those calculated by the PLAXIS 3D software and GEO-Studio software. The results show that the permanent displacement calculated by this method is close to that calculated by the GEO-Studio software, and the difference is only 2%, and thus, the rationality of the proposed method for calculating the permanent displacement of the multi-stage loess slope under the action of earthquake is verified. The algorithm proposed in this paper provides a theoretical reference for the calculation of the permanent displacement of multi-stage loess slope under the action of earthquake.